Booster giving the player the 2.0 was the hardest thing for me, I remember being horrified about how he basically gives up and passes his last saving grace onto you. I remember in the normal ending, getting the 0.8 and feeling determined to avenge him like with King how he gives you his blade. But it's true horror to see a man literally give up in front of your eyes, and later on when you talk to Kazuma, a man who seemed pretty chilled; turns into this mess who gives up to, knowing he has a dragon to escape. He even invites you to join him, abandoning his family and friends for his own survival which sickened me when I first saw it. I think, that's a true character and a true conflict between somebody who would rather save his life than risk it to save others.
Misery becomes vulnerable and desperate to keep her image as a threatening figure and to see it fall apart after the Doctor returns as the red energy is chilling. It all boils up in the final battle between you, your friend, a desperate enemy, and an insane psycho who disregards anything around him, only wishing for his plan to succeed. I like Ballos' fight, but it's more frustrating than energized; The Undead Core battle is something of a spectacle, you fight two creatures and along that, a monster who's insane.
Pixel knows how to make his villains climatic and amazing. In Kero Blaster, he depicts a world where his characters are over-worked and are struggling to survive, as seen in in the Overtime story-line and most importantly with the President. I see Guxt as a spiritual successor to Cave Story in terms of theme, I see the story unfolding as a lone ship taking down watchers, and the ship's struggle to battle an army alone. It's final boss is something only Pixel could do; with the final boss' eye being orange, contrasting the game's blue/white aesthetic and having it attack the player only to then reveal a face similar to the Doctor's (probably a coincidence) with a smirk as you battle it to the death. Cave Story follows a mad scientist and his conquest that leads up to this epic final battle, saying "YOU WILL NOT LEAVE THIS PLACE ALIVE", being extremely threatening and imposing of his supernatural status. I see his lines leaving a greater impact on me than Flowey's "It's kill or be killed.", to me, it comes off as edgy and while I understand it works to Flowey's nature, the Doctor is merely a psycho, doing whatever he pleasure and taking joy out of the suffering of others with a imposing demeanor; appearing at the right times to leave an impact when absolutely needed to drive the plot in a good way.